STONE MOUNTAIN, Ga. — Hundreds of school bus drivers here participated in a days-long "sick-out" designed to address concerns over pay and retirement benefits.

On Thursday, the first day of the sick-out, 383 DeKalb County School District bus drivers called in sick to work, according to the Atlanta Journal-Constitution. Friday saw a decrease in the number of drivers who called out, at 224, and by Monday, the final day of the sick-out, that number had dwindled to only 63 drivers taking part. The school district has a total of 908 full-time and substitute bus drivers, the newspaper reports.

The school district published a message to parents on its website stating that it had a contingency plan during the sick-out and was meeting with school bus drivers and transportation staff members to address their concerns.

Seven school bus drivers were fired for reportedly staging the demonstration, WABE reports. One bus driver who received a call at the end of the day on Thursday saying that her job was terminated, told the Atlanta Journal-Constitution that she felt that she and others were targeted for speaking up at a meeting between Stephen Green, the superintendent of the school district, and about 400 drivers.

DeKalb County School District stated on its website that its bus drivers earn the second-highest hourly compensation in the region, receive several benefits, and have opportunities for career growth.

Green said in a letter to parents on Monday that he met with an at-large school bus driver group and a subgroup of drivers last week to address their concerns. The letter also included a fact sheet that said that a Driver and Monitor Advisory Committee was established 15 years ago to “receive, review and act on concerns from bus drivers related to their employment as a group” and provided a timeline of recent meetings.

The fact sheet includes further details on school bus driver benefits, stating that the district’s drivers received five cost-of-living adjustments in pay and minimum wage increases since 2014; and in addition to health care and retirement benefits, they receive dental, vision, disability, and long-term care insurance; and sick leave, personal leave, and vacation leave. It also mentions that the district added field support supervisors to help manage daily operations and hired more school bus mechanics; partnered with the National Association for Pupil Transportation on the Transportation Leadership Academy to provide opportunities for career advancement; and is working on projects to increase efficiency, such as optimizing bell times and a parent notification app.

Green and school bus driver representatives are expected to meet again on Thursday, and, according to WABE, the superintendent said that he will give drivers some time to provide a doctor’s note before enacting a tiered punishment system.